update tablename set feild1=' ' where field2=(select field2 from table2 where no=' ')

[Sharma Neha]

I hav a problem in sql query.I m using C#.net and working on window form,Database is SqlSever.
There is a table tracking which has key_no,status as its field.
There is another table master which has slno,key_no,etc as its field.

In my form i hav a textbox in which one enters slno,so using this slno i want to get key_no from master table using Select query and then use this key_no to update the status in tracking table.

I have used the code which is written below,but it is not updating the value in the table tracking.

SqlConnection cn = new SqlConnection();
cn.ConnectionString = "Data Source= abc ;Database= def;uid=pro;pwd=ghg";
cn.Open();
string sql = "update rock set status='INVG' where key_no=(select key_no from master where slno=@slno)";
SqlCommand cmd= new SqlCommand(sql, cn);
cmd.Parameters.AddWithValue("@slno", Convert.ToInt32(textBox2.Text)); 
SqlDataAdapter ds = new SqlDataAdapter(k);
ds.Fill(dd); /*dd is a instance of DataTable*/
MessageBox.Show("Record updated");
cn.Close();

plzzz help.........

[Sharma Neha]

thanks u all for the co-operation,well i hav solved this query so there is now no need to send me reply for this query.